Disclosure is in native lore (10)
I believe the answer is:
revelation
'disclosure' is the definition.
(I know that disclosure can be written as revelation)
'is in native lore' is the wordplay.
'is in' indicates anagramming the letters (the answer is anagrammed in those letters).
'native'+'lore'='nativelore'
'nativelore' is an anagram of 'REVELATION'.
(Other definitions for revelation that I've seen before include "joy?" , "Suprising disclosure" , "NT book" , "enlightening book?" , "enlightening experience" .)